French republican calendar

The French republican calendar was instituted by the National Convention after the French Revolution as a reform of the Gregorian calendar that would help to divorce the new republic from its Catholic predecessor.

The creation of the calendar

In 1793, the National Convention's Committee of Public Instruction created a subcommitte, chaired by the mathematician Charles Gilbert Romme, to create a new calendar. Other members were Louis Lagrange and Gaspard Monge, also mathematicians; the scientists Antoine François Fourcroy, Guyton de Morveau, Joseph Jérôme le François de Lelande, and Joseph Lakanal; and the poets Marie-Joseph de Chénier and Philip François Nazaire Fabre d'Églantine.

Romme presented the results, first to the Committee of Public Instruction and then to the full Convention, in September of 1793, and the Convention issued a decree on October 5th that made the calendar official. The names of days and months were finalized by a decree on November 24th.

Its structure

Start of the year

Year I was deemed to have on September 22, 1792 Gregorian, the date of the founding of the Republic, and also the fall equinox of that year. Each following year was to start at midnight of the day of the fall equinox, as observed at the Paris Observatory.

Months and days

A year was divided into 12 months of 30 days each, with five epagomenal days, six in leap years. Each month consisted of three décades, or 10-day weeks, with days named Primdi, Duodi, Tridi, Quartidi, Quintidi, Sextidi, Septidi, Octidi, Nonidi, and Decadi ("First Day", "Second Day", etc.). Every Decadi was to be a rest day. Fabre d'Églantine named the days and months as follows. Note that every Quintidi was named for an animal, and every Decadi for a farming tool.

Fall months
		Name	(English name)	Name	(English name)	Name	(English name)
Months		Vendemaire	Vintage	Brumaire	Foggy	Frimaire	Frosty
Primdi	1	Raisin	Grape	Pomme	Apple	Raiponce	Rampion
Duodi	2	Safran	Crocus	Céleri	Celery	Turneps	Field-turnips
Tridi	3	Châtaignes	Chestnut tree	Poire	Pear	Chicorée	Chicory
Quartidi	4	Colchiques	Autumn crocus	Bettrave	Beet	Nèfle	Medlar
Quintidi	5	Cheval	Horse	Oie	Goose	Cochon	Pig
Sextidi	6	Balsamine	Balsam	Héliotrope	Heliotrope	Mâche	Lamb's lettuce
Septidi	7	Carottes	Carrots	Figue	Fig	Chou-fleur	Cauliflower
Octidi	8	Amarante	Amaranth	Scorsonère	Black salsify	Miel	Honey
Nonidi	9	Panais	Parsnip	Alisier	Sorb	Genièvre	Juniper
Decadi	10	Cuve	Tank	Charrue	Plow	Pioche	Mattock
Primdi	11	Pome-de-Terre	Potato	Salsifis	Salsify	Cire	Wax
Duodi	12	Immortelle	Immortelle	Macre	Water chestnut	Raifort	Horseradish
Tridi	13	Potiron	Winter squash	Topinambour	Jerusalem artichoke	Cèdre	Cedar
Quartidi	14	Réséda	Mignonette	Endive	Endive	Sapin	Fir
Quintidi	15	Ane	Donkey	Dindon	Turkey	Chevreuil	Deer
Sextidi	16	Belle-de-nuit	Pretty-by-night	Chervis	Caraway	Ajonc	Gorse
Septidi	17	Citrouille	Pumpkin	Cresson	Watercress	Cyprès	Cypress
Octidi	18	Sarrasin	Buckwheat	Dentelaire	Leadwort	Lierre	Ivy
Nonidi	19	Tournesol	Sunflower	Grenade	Pomegranate	Sabine	Savin
Decadi	20	Pressoir	Pressing shed	Herse	Harrow	Hoyau	Hoe
Primdi	21	Chanvre	Hemp	Bacchante	Bacchante	Erable-sucre	Maple syrup
Duodi	22	Pêche	Peach	Azerole	Azarole	Bruyère	Heather
Tridi	23	Navet	Turnip	Garance	Madder	Roseau	Reed
Quartidi	24	Amaryllis	Amaryllis	Orange	Orange	Oseille	Sorrel
Quintidi	25	Boeuf	Steer	Faisan	Pheasant	Grillon	Cricket
Sextidi	26	Aubergine	Eggplant	Pistache	Pistachio	Pingon	Pine nut
Septidi	27	Piment	Red pepper	Macjonc		Liége	Cork
Octidi	28	Tomate	Tomato	Coing	Quince	Truffe	Truffle
Nonidi	29	Orge	Barley	Cormier	Sorb tree	Olive	Olive
Decadi	30	Tonneau	Barrel	Rouleau	Rolling pin	Pelle	Shovel
Winter months
		Name	(English name)	Name	(English name)	Name	(English name)
Months		Nivôse	Snowy	Pluviôse	Rainy	Ventôse	Windy
Primdi	1	Tourbe	Peat	Lauréole	Daphne	Tussilage	Coltsfoot
Duodi	2	Houile	Coal	Mousse	Moss	Cornouiller	Dogwood
Tridi	3	Bitume	Bitumen	Fragon	Butcher's broom	Violier	Wallflower
Quartidi	4	Soufre	Sulfur	Perce-neige	Snowdrop	Troëne	Privet
Quintidi	5	Chien	Dog	Taureau	Bull	Bouc	Billygoat
Sextidi	6	Lave	Lava	Laurier-thym	Viburnum	Asaret	Azarum
Septidi	7	Terre végétale	Topsoil	Amadouvier	Tinder agaric	Alaterne	Buckthorn
Octidi	8	Fumier	Manure	Mèzéréon	Mezereon	Violette	Violet
Nonidi	9	Salpêtre	Saltpeter	Peuplier	Poplar	Marceau	Goat willow
Decadi	10	Fléa	Flail	Coignée	Axe	Beche	Garden fork
Primdi	11	Granit	Granite	Ellebore	Hellebore	Narcisse	Narcissus
Duodi	12	Argile	Clay	Brocoli	Broccoli	Orme	Elm
Tridi	13	Ardoise	Slate	Laurier	Laurel	Fumeterre	Fumus terrae
Quartidi	14	Grès	Sandstone	Avelinier	Filbert tree	Vélard	Hedge-mustard
Quintidi	15	Lapin	Rabbit	Vache	Cow	Chèvre	Nanny goat
Sextidi	16	Silex	Flint	Buis	Box tree	Epinards	Spinach
Septidi	17	Marne	Marl	Lichen	Lichen	Doronic	Leopard's bane
Octidi	18	Pierre à chaux	Limestone	If	Yew	Mouron	Pimpernel
Nonidi	19	Marbre	Marble	Pulmonaire	Lungwort	Cerfeuil	Chervil
Decadi	20	Van	Winnowing basket	Serpette	Pruning knife	Cordeau	Cord
Primdi	21	Pierre à plâtre	Gypsum	Thlaspi	Pennycress	Mandragore	Mandrake
Duodi	22	Sel	Salt	Thimelé		Persil	Parsley
Tridi	23	Fer	Iron	Chiendent	Couch grass	Cochléaria	Cochlearia
Quartidi	24	Cuivre	Copper	Traînasse	Knotgrass	Pâquerette	Daisy
Quintidi	25	Chat	Cat	Lièvre	Hare	Thon	Tuna
Sextidi	26	Etain	Tin	Guède	Woad	Pissenlit	Dandelion
Septidi	27	Plomb	Lead	Noisetier	Hazel	Silvie	Forest
Octidi	28	Zinc	Zinc	Cyclamen	Cyclamen	Capillaire	Maidenhair fern
Nonidi	29	Mercure	Mercury	Chéledoine	Celandine	Frène	Ash
Decadi	30	Crible	Sifting screen	Traineau	Sleigh	Plantoir	Dibble
Spring months
		Name	(English name)	Name	(English name)	Name	(English name)
Months		Germinal	Seedtime	Floréal	Flowery	Prairial	Meadowy
Primdi	1	Primevère	Primrose	Rose	Rose	Luzerne	Alfalfa
Duodi	2	Platane	Plane tree	Chêne	Oak	Hémérocale	Day-lily
Tridi	3	Asperges	Asparagus	Fougère	Fern	Trèfle	Clover
Quartidi	4	Tulipes	Tulips	Aubépine	Hawthorn	Angélique	Angelica
Quintidi	5	Poule	Hen	Rossignol	Nightingale	Canard	Duck
Sextidi	6	Blette	Swiss chard	Ancolie	Columbine	Mélisse	Melissa
Septidi	7	Bouleau	Birch	Muguet	Lily of the valley	Fromental	Wheat
Octidi	8	Jonquille	Daffodil	Champignon	Mushroom	Martagon	Martagon
Nonidi	9	Aune	Alder	Hyacinthe	Hyacinth	Serpolet	Wild thyme
Decadi	10	Couvoir	Incubator	Rateau	Rake	Faux	Scythe
Primdi	11	Pervenche	Periwinkle	Rhubarbe	Rhubarb	Fraise	Strawberry
Duodi	12	Charme	Hornbeam	Sainfoin	Fodder	Bétoine	Betony
Tridi	13	Morille	Morel	Bâton-d'or	Goldenrod	Poix	Pitch
Quartidi	14	Hêtre	Beech	Chamérisier	Dwarf palm	Acacia	Locust tree
Quintidi	15	Abeille	Honeybee	Ver-à-soie	Silkworm	Caille	Quail
Sextidi	16	Laitue	Lettuce	Consoude	Comfrey	Oeillet	Carnation
Septidi	17	Mélèze	Larch	Pimprenelle	Burnet	Sureau	Elder tree
Octidi	18	Ciguë	Hemlock	Corbeille-d'or	Yellow alyssum	Pavot	Poppy
Nonidi	19	Radis	Radish	Arroche	Mountain spinach	Tilleul	Lime tree
Decadi	20	Ruche	Beehive	Sarcloir	Hoe	Fourche	Pitchfork
Primdi	21	Gainier	Judas tree	Statice	Statice	Barbeau	Cornflower
Duodi	22	Romaine	Romaine lettuce	Fritillaire	Fritillary	Camomille	Chamomile
Tridi	23	Maronnier	Chestnut tree	Bourrache	Borage	Chèvrefeuille	Honeysuckle
Quartidi	24	Roquette	Rocket plant	Valériane	Valerian	Caille-lait	Rennet
Quintidi	25	Pigeon	Pigeon	Carpe	Carp	Tanche	Tench
Sextidi	26	Anémone	Anemone	Fusain	Charcoal	Jasmin	Jasmine
Septidi	27	Lilas	Lilac	Civette	Chives	Verveine	Verbena
Octidi	28	Pensée	Pansy	Buglose	Bugloss	Thym	Thyme
Nonidi	29	Myrtille	Blueberry	Sénevé	Wild mustard	Pivoine	Peony
Decadi	30	Greffoir	Grafting knife	Loulette	Shepherd's crook	Chariot	Wagon
Summer months
		Name	(English name)	Name	(English name)	Name	(English name)
Months		Messidor	Harvest	Thermidor	Hot	Fructidor	Fruit
Primdi	1	Sigle	Rye	Epeautre	Spelt	Prune	Plum
Duodi	2	Avoine	Oats	Bouillon blanc	Mullein	Millet	Millet
Tridi	3	Oignon	Onion	Melon	Melon	Lycoperde	Puff-ball
Quartidi	4	Véronique	Speedwell	Ivraie	Rye grass	Escourgen	Winter barley
Quintidi	5	Mulet	Mule	Bélier	Ram	Saumon	Salmon
Sextidi	6	Romarin	Rosemary	Prêle	Horsetail	Tubéreuse	Tuber
Septidi	7	Concombre	Cucumber	Armoise	Artemisia	Sucrion	Sugar melon
Octidi	8	Echalottes	Shallots	Carthame	Safflower	Apocyn	Dog bane
Nonidi	9	Absynthe	Absinthe	Mûres	Mulberries	Réglisse	Licorice
Decadi	10	Faucille	Sickle	Arrosoir	Watering can	Echelle	Ladder
Primdi	11	Coriandre	Coriander	Panis	Panic grass	Pastrèque	Watermelon
Duodi	12	Artichaut	Artichoke	Salicot		Fenouil	Fennel
Tridi	13	Giroflée	Wallflower	Apricot	Apricot	Epine-vinette	Barberry
Quartidi	14	Lavande	Lavender	Basilic	Basil	Noix	Walnut
Quintidi	15	Chamois	Fawn	Brebis	Ewe	Truite	Trout
Sextidi	16	Tabac	Tobacco	Guimauve	Marshmallow	Citron	Lemon
Septidi	17	Groseille	Red currant	Lin	Flax	Cardière	Teasel
Octidi	18	Gesse	Vetch	Amande	Almond	Nerprun	Buckthorn
Nonidi	19	Cerise	Cherry	Gentiane	Gentian	Tagette	Indian rose
Decadi	20	Parc	Pen (enclosure)	Ecluse	Lock	Hotte	Sack
Primdi	21	Menthe	Mint	Carline	Thistle	Eglantier	Dog rose
Duodi	22	Cumin	Cumin	Caprier	Caper shrub	Noisette	Hazelnut
Tridi	23	Haricots	Beans	Lentille	Lentil	Houblon	Hops
Quartidi	24	Orcanète	Dyer's bugloss	Aunée	Elecampane	Sorgho	Sorghum
Quintidi	25	Pintade	Guinea fowl	Loutre	Otter	Écrivisse	Crayfish
Sextidi	26	Sauge	Sage	Myrte	Myrtle	Bigarade	Bitter orange
Septidi	27	Ail	Garlic	Colza	Canola oil	Verge d'or	Goldenrod
Octidi	28	Vesce	Vetch	Lupin	Lupin	Maïs	Maize
Nonidi	29	Blé	Wheat	Coton	Cotton	Marron	Horse chestnut
Decadi	30	Chalémie		Moulin	Mill	Panier	Basket

The epagomenal days were originally called sanculotides ("days of the sans-culottes"; modern spelling, sans-culottides). They were named Fête du Vertu ("Festival of Virtue"), Fête du Génie ("Festival of Genius"), Fête du Travail ("Festival of Work"), Fête de l'Opinion ("Festival of Opinion"), Fête des Récompenses ("Festival of Rewards"), and Fête du Révolution ("Festival of the Revolution"). These were to be public holidays, and Fête du Révolution, the leap day, was to be a day of games between competitors from all over France.

Leap years

Leap years, called "sextile years" because of the six epagomenal days, were to occur every four years, with the first being year III. A group of four years was to be known as a Franciade. However, as was quickly pointed out by the astronomer Jean Baptiste Joseph Delambre, there was no way to reconcile this with the desire to begin every new year on the equinox. In response, Romme formed a new subcommittee to "perfect" the calendar. It ultimately proposed to follow the Gregorian pattern of leap years, with the exception of suppressing one leap day every 4000 years. Before the recommendation could be implemented, however, Romme was arrested and sentenced to death.

Its demise

The republican calendar was deeply unpopular both inside and outside France and its conquered territories for the difficulties it caused in communicating and doing business with the rest of Europe. The working people of France were also unhappy about having only one day of rest in every ten.

The décade was the first part of the calendar to go, in 1795. Also in that year, the sanculotides were renamed simply jours supplémentaires ("extra days").

Napoleon exempted Rome from the new calendar in 1799, to placate the Pope. In 1805, now emperor, he restored France to Catholicism and restored the old calendar. France officially rejoined the Gregorian world on January 1st, 1806.